1. Field of the Invention
The present invention relates to a lens-fitted photo film unit. More particularly, the present invention relates to a lens-fitted photo film unit in which a front cover is transparent for newly designing the appearance of the product.
2. Description Related to the Prior Art
A lens-fitted photo film unit is pre-loaded with unexposed photo film, and incorporates mechanisms for taking exposures. A lens-fitted photo film unit is characterized in that, when a user purchases it, he or she can take photographs readily and easily. The lens-fitted photo film unit is used widely mainly because of its usefulness.
In a photographic camera, a field frame indicia is observable inside a viewfinder optical system to indicate a photographable region for taking an exposure on photo film. In FIG. 10, a viewfinder objective opening 14 has an opening edge 14a, and limits a light flux of object light incident upon an objective lens 31a. The opening edge 14a makes it possible to observe only the photographable region when a user observes a photographic field through a viewfinder eyepiece opening 18. Note that a base member 30a of an exposure unit is located between a front cover 22 and a rear cover 23, and supports an eyepiece lens 31b combined with the objective lens 31a. 
Various ideas for modifying the lens-fitted photo film unit are conceived. To change its appearance, it may be conceivable to produce some of plastic parts in a transparent manner, which is known as a skeleton type. In particular, transparency of the front cover may be conceivable in the lens-fitted photo film unit. This is because the photo film must be contained therein. It is necessary to keep the light-tightness of a main body, the rear cover and the exposure unit in view of shielding light from a photographic light path and chambers for accommodating the photo film.
However, a problem arises in that the transparency of the front cover makes the opening edge of the viewfinder objective window unclear to an eye of a user observing through the viewfinder. A region that can be photographed becomes not discernible to the user.
For the resin for molding the front cover, polystyrene resin is the most preferable because of a low manufacturing cost and suitability for recycling, the polystyrene resin having been widely used for molding the front and rear covers. However, a totally transparent piece molded from the polystyrene resin is considerably fragile, and cannot have a sufficiently high shock strength.
In view of the foregoing problems, an object of the present invention is to provide a lens-fitted photo film unit in which a front cover is transparent, and also an photographable region in a viewfinder is clearly discernible to a user.
Another object of the present invention is to provide a lens-fitted photo film unit in which a front cover is transparent, and also which has a high shock strength.
Still another object of the present invention is to provide a lens-fitted photo film unit in which a front cover is transparent, and also an outer packaging member has a suitable appearance in combination with the front cover.
In order to achieve the above and other objects and advantages of this invention, a lens-fitted photo film unit includes an opaque main body pre-loaded with photo film. An opaque rear cover covers a rear of the main body. A front cover covers a front of the main body. A viewfinder eyepiece opening is formed through the rear cover. A viewfinder objective window is formed in the front cover, combined with the viewfinder eyepiece opening, and adapted to observation of a photographic field. At least a portion of the front cover is produced from material for transmitting light therethrough. A field frame portion is disposed on an edge of the viewfinder objective window, visible through the viewfinder eyepiece opening, for indicating a photographable region in the photographic field.
Furthermore, the material for the front cover is resin that is colorless and transparent or is colored and transparent.
A housing is constituted by combining the main body, the rear cover and the front cover. There is an outer packaging member, of which at least a portion is produced from material for transmitting light therethrough, and which is secured to an outside of the housing.
The field frame portion is produced from material for absorbing at least part of light incident thereon, and an inside of the field frame portion defines the photographable region.
By this construction, the photographable region in a viewfinder is clearly discernible to a user, because the field frame portion can been recognized by an eye of a user observing the photographic field through the viewfinder.
The material for the field frame portion is resin.
The field frame portion is a frame-shaped member, and has a frame-shaped inclined surface inclined at a predetermined incident angle with reference to the viewfinder objective window.
The viewfinder objective window is a viewfinder objective opening formed through the front cover.
According to a preferred embodiment, the front cover is colorless and transparent, and the viewfinder objective window is a plate-shaped portion of the front cover.
According to another preferred embodiment, the field frame portion is a frame-shaped plate secured to a rear of an edge of the viewfinder objective window.
The frame-shaped plate is produced by pressing.
The frame-shaped plate is fixedly positioned on the front cover by use of one of forced insertion, caulking, welding and insert molding.
According to a further preferred embodiment, the field frame portion is a frame-shaped coating pattern disposed on a front of an edge of the viewfinder objective window.
The outer packaging member has at least a portion disposed on a front face of the front cover. The coating pattern is formed on a portion of the outer packaging member disposed on a periphery of the viewfinder objective window.
According to another preferred embodiment, the outer packaging member has at least a portion disposed on a front face of the front cover. Furthermore, an outer opening is formed in the outer packaging member, disposed in front of the viewfinder objective window, the outer opening being smaller than the viewfinder objective window, and having an edge for constituting the field frame portion.
According to an additional preferred embodiment, the outer packaging member has at least a portion disposed on a front face of the front cover. Furthermore, an outer opening is formed in the outer packaging member, for uncovering the viewfinder objective window.
The front cover is colorless and transparent, and the outer packaging member is colored and transparent.
According to another preferred embodiment, the front cover is colored and transparent, and the outer packaging member is colored and transparent.
The viewfinder objective window is a viewfinder objective opening formed through the front cover, and having an edge for constituting the field frame portion.
According to still another preferred embodiment, the front cover is colorless and transparent, and the outer packaging member is colorless and transparent.
According to another preferred embodiment, the front cover is colored and transparent, and the outer packaging member is colorless and transparent.
By this construction, the outer packaging member has a suitable appearance in combination with the front cover because of their transparency.
The outer packaging member is belt-shaped, and fitted on a rear, a front, a top and a bottom of the housing.
The material for the outer packaging member is resin.
The resin of the front cover is ABS resin, or copolymer resin obtained by copolymerization of polystyrene resin and acrylic resin.
By this construction, the front cover has a high shock strength.
The front cover has outer and inner surfaces one of which has surface roughness, and is translucent.
According to another aspect of the present invention, a lens-fitted photo film unit includes a housing pre-loaded with photo film in a light-tight manner. An opaque rear cover constitutes a rear of the housing. A front cover constitutes a front of the housing, at least a portion of the front cover being produced from material for transmitting light therethrough. An outer packaging member is secured to an outside of the housing, at least a portion of the outer packaging member being produced from material for transmitting light therethrough.